Amplification of terahertz radiation in carbon nanotubes Sulemana S. Abukari, Kofi W. Adu, Samuel Y. Mensah, Natalia G. Mensah, Kwadwo A. Dompreh, Anthony Twum and Musah Rabiu Eur. Phys. J. B, 86 4 (2013) 182 Published online: 24 April 2013 DOI: 10.1140/epjb/e2013-30771-6